The round includes participation from existing investors Oak Investment Partners, Archer Venture Acquisitions and John Battelle.

The financing, which includes the conversion of a convertible note, follows year over year revenue growth of 90% in the second quarter and four consecutive quarters of positive EBITDA performance. The additional capital will be used to accelerate both organic and inorganic growth opportunities.

'We see exciting areas for growth in the ad tech market and we wanted to buttress our already strong balance sheet in order to quickly take advantage of opportunities,' said Walter Knapp, CEO of sovrn Holdings. 'Our board, which includes some of the smartest investors in ad tech and media, agrees. Their investment in sovrn is a clear endorsement of that position.'

According to research site eMarketer, in 2015 US programmatic digital display ad spending will eclipse the $10 billion mark.

'Increasing our investment in sovrn is a reflection of our belief that companies with scale, good margin dynamics and innovative technology will be the winners in ad tech,' said Seth Levine of Foundry Group. 'We're seeing a clear bifurcation in the ad tech market with a stark differentiation between successful companies and those that will fail. sovrn has built a profitable and very rapidly growing business that we're excited to be a part of.'

About sovrn

sovrn believes independent publishers drive the Internet's creativity and innovation. As a partner and advocate to independent publishers, sovrn provides tools and services that help publishers better understand, grow and engage their readers and enable them to monetize their sites through programmatic advertising. With one billion ad transactions everyday, sovrn's network of independent publishers provides advertisers with massive reach and the ability to engage with difficult-to-reach audiences on the sites they love. sovrn is headquartered in Boulder, Colo. with offices in Denver, San Francisco and New York. For more information, please visit http://sovrn.com or follow on Twitter @sovrnHoldings.